John Brennan couldn't get a word in at first. When he did finally did, he defended the Obama administration's controversial drone program.

As his confirmation hearing got under way before the Senate Intelligence Committee today, President Obama's nominee to lead the CIA was confronted by protesters for his role in overseeing the classified drone program that targets terrorists, including U.S. citizens.

But the hearing was shut down for a few minutes after protesters -- apparently hailing from the war-protest group Code Pink -- interrupted the proceedings five times. They rose, one by one, to interrupt Brennan as he began his testimony, then stopped him four more times, or every time he resumed speaking.

The same group protested against former Secretary of State Condoleezza Rice when she testified before Congress in 2007. A member held fake-bloodied hands in her face, yelling "war criminal."

Sen. Diane Feinstein, D-Calif., the committee chairwoman, ordered all hearing observers to leave the room and be readmitted. Code Pink members, all seated in the same row, were removed.

Brennan's hearing came at a controversial time for the U.S. intelligence community. It was revealed this week that a secret White House memo authorized the killing of U.S. citizens abroad. Obama will make that memo available to members of the Senate Intelligence Committee.

Feinstein defended drone strikes as the hearing began, lamenting that she was unable to publicize the administration's classified figures on collateral civilian deaths resulting from drone strikes.

"The figures we have obtained from the executive branch, which we have done our utmost to verify, confirm the civilian casualties that result from these strikes each year have typically been in the single digits," Feinstein said.

Once the hearing got under way, Brennan defended America's drone program while calling for greater transparency.

"I believe there are people who believe we take strikes to punish terrorists for past transgressions. Nothing could be further from the truth," Brennan said. "The people who are standing up here today, I think, have a misunderstanding of what we do as a government."

On the controversial topic of killing American citizens, Brennan again defended the administration. With news of the memo justifying such action, the 2011 killing in Yemen of American al Qaeda operative Anwar al Awlaki has attained renewed controversy.

"Any American who joins al Qaeda will know full well that they have joined an organization that is at war with the United States," Brennan said. "Any American who did that should know well that they in fact are part of an enemy ... and that the U.S. will do anything that is possible to destroy that enemy to save American lives."

Senators also asked Brennan whether the CIA's enhanced interrogation program, to which Brennan has been linked, yielded intelligence that led to the killing of Osama bin Laden. Committee Democrats, who released a 6,000 page report on the matter, have protested that enhanced interrogations did not yield meaningful intelligence.

After reading the 300-page summary of that report, Brennan said he's not sure.

"There clearly were a number of things, many things that I read in that report that are very concerning and disturbing to me, and ones that I would want to look into immediately," Brennan told Feinstein.

Brennan said he had previously thought enhanced interrogations helped in the bin Laden search, based on information he was given at the time. Brennan told one senator that the report has cast doubt on what he was told.

"At this point, senator," Brennan said, "I do not know what the truth is."

Pressed by Sen. Carl Levin on the practice of waterboarding, Brennan would not say whether or not he believes it qualifies as "torture," but Brennan did express disgust with the practice and said it would not occur under his watch at the CIA.

"It is reprehensible and something that should not be done," Brennan said. "Waterboarding is something that should have never been employed, and as far as I'm concerned, something that never would be if I were confirmed."

Brennan also warned of catastrophic consequences of the looming budget sequestration, which will happen on March 1 unless Congress agrees to deficit-reduction measures or passes a temporary fix.

"It's going to have a devastating impact on the national security of this country," Brennan said.